Cards like Spyglass Siren and Nutrient Block provide early board presence and artifacts, while Chrome Companion leaves a token behind when it dies, ensuring we always have artifacts to power our synergies
Matthew Byrd, writing for Den of Geek , stated that a lot of design work had gone into the Pokmon that were eventually cut, suggesting that Game Freak might have taken them out during the testing phase due to balance issues
Of course I could be wrong EDIT: I too would welcome any knowledge of these as it relates to the pokemon tcg

Advanced Search Sets Random Syntax Aberrant Argothian Enchantress Ashiok's Reaper Astral Drift Bello, Bard of the Brambles Bucket List (playtest) Chakra Meditation Champions from Beyond Charitable Levy Communal Brewing Confounding Conundrum Corruption of Towashi Creepy Crawler (playtest) Decree of Silence Demonic Covenant Disinformation Campaign Dovin's Acuity Eidolon of Blossoms Ellivere of the Wild Court Enchantress's Presence Enduring Curiosity Enduring Innocence Entity Tracker Ephara, Ever-Sheltering Extraordinary Journey Femeref Enchantress Firemind's Research Fleeting Memories Freyalise's Charm Frostcliff Siege Fugitive Druid Garruk's Uprising Glissa Sunslayer Guild Summit Hollowmurk Siege Hoofprints of the Stag Ineffable Blessing Ineffable Blessing Ineffable Blessing Ineffable Blessing Ineffable Blessing Ineffable Blessing Intimidation Campaign Invasion Tactics Kestia, the Cultivator Killian, Decisive Mentor Kindred Discovery Lost Isle Calling Mesa Enchantress Mirrodin Besieged Narci, Fable Singer Niko Aris Oath of Lim-Dl Obsessive Pursuit Ominous Seas Pearl-Ear, Imperial Advisor Phenomenon Investigators Political Triumph Quint's Insight Rewrite History Rite of Harmony Robot Domination Satyr Enchanter Setessan Champion Shadow of the Goblin Shoal Kraken Sigarda's Splendor Sparring Regimen Stocking the Pantry Struggle for Project Purity Sythis, Harvest's Hand Tameshi, Reality Architect

During the game, if the card is in a public zone, swap in the real card
I am very partial to Black